Learn Spanish (Latin America): Al ver el escudo, lo activas. - Upon seeing the shield, you activate it.

The formula al + infinitive is a very common way in Spanish to say 'upon doing [something]' or 'when doing [something]'. Even though ver is the base form ('to see'), combining it with al turns it into an action happening at the exact same time as the main verb.

Could I just say Cuando ves el escudo instead of Al ver el escudo?

Yes, Cuando ves el escudo (When you see the shield) means practically the same thing! Using al + infinitive is just a slightly more concise way to connect two actions that happen right next to each other. Notice that with al ver, you don't need to specify who is seeing the shield until the second half of the sentence (activas).

Why does lo come before the verb in lo activas?

Lo is a direct object pronoun replacing el escudo (the shield). In Spanish, these pronouns usually must go immediately before a conjugated verb. You can attach pronouns to the end of an infinitive or an affirmative command, but since activas is a standard conjugated present tense verb, lo has to go in front.

Why use the present tense activas if this sounds like a future instruction?

In Spanish, the present tense is often used to give instructions, state rules, or describe what happens in conditional situations (like a video game tutorial). It translates smoothly to 'you activate it', implying that this is the required action every time you see the shield.